William j



(No Model.) 7

W. J. RAFFERTY.

' SMOKE GONSUMING FURNACE. NO. 390,252. Patented 0013. 2, 1888.

M62906 5866. ai j [raven/Z57":

UNITED STATES PATENT OFFICE.

WILLIAM J. RAFFERTY, or cHIcAeo, ILLINoIs, AssIcNoR or oNE-IIALF To THOMAS o. LOUOKS, nLsoN 0. JENNINGS, AND CHRISTOPHER WHALEN,

OF SA ME PLACE.

SMOKDE-CONSUMING FURNACE.

SIPECIEICATION forming part of Letters Patent No. 390,252, dated October 2, 1888.

Application filed Octcber22, 1887.

To all whom it may concern.-

Be it known that 1, WILLIAM J. RAFFER'IY, of Chicago. in the county of Cook and State of Illinois, have invented certain new and useful Improvements in Smoke-Consuming Furnaces, of which the following is a description, reference being bad to theaccompanying drawings, forming a part of this specification, in which- Figure 1 is a side view of a furnace and boiler embodying my improvement, the walls of said furnace being shown in longitudinal section. Fig. 2 is a plan view of the furnace, the boiler being removed from the walls; and Fig. 3 is I 5 an enlarged vertical sectional view in detail of a portion of the wall above the door and the steam-pipe inserted therein.

Like letters of reference designate corresponding parts.

My invention relates particularly to boilerfurnaces; and my object is to so construct the same as to produce perfect and complete combustion, thereby rendering the furnace smokeless. I accomplish said object in the manner hereinafter more particularly shown and described.

A in the drawings represents the usual outer walls of the furnace; B, the bridgewall; O, the grate, and D the boiler, set in the walls or casings in the usual manner.

E and F are doors opening to the fire and ash-pit, respectively, and both of which are provided with registers or slide-openings e f, for regulating the admission of air to the fire. Instead of constructing a solid bridge-wall, as is usually done, I make said wall ho11ow,or, rather, form a chamber or cavity, G, therein, which cavity I prefer to make larger at the bottom and gradually taper the same until it 0 reaches the top, as clearly shown in the drawings. At or near the bottom of said chamber I provide one or more, but preferably a series, of openings, H, leading from the front of the bridge-wall beneath the grate into the said 5 chamber G, and by preference entirely through the bridge-wall to the combustion-chamber J in the rear of said bridge-wall.

The top of the bridge-wall I prefer to construct in the form of an inverted arch, to conform to the shape of the exterior of the boiler.

Serial No. 253,053. (No model.)

D is asteam-pipe connecting with the steamdome D and leading to the front of the furnace. where it connects with a horizontal pipe,

D, which is in turn tapped by short pipes or jets d ,which pierce the wall A and are directed toward the top of the bridge-wall, so that the steam-jets therefrom may converge at or about that point. Said pipes 01 are preferably surrounded by pipes or coverings d'to protect them from the action of the heat. A stop-valve, (Z is providedin the pipe D to regulate the admission of steam to the jets.

The operation of said furnace is as'follows:

In addition to the volume of air admitted above the grate to support combustion, a considerable portion of the air admitted through the door F beneath the grate passes through the openings II into the chamber G, and thence upwardly, as indicated by the arrow, until it meets and commingles with the products of combustion passing over the bridge-wall and at the point of greatest heat, where a sufficient amount of oxygen combines with the carbon to prevent the formation of smoke. Should any carbon pass over the bridge-wall unconsumed, it tends, by forming an eddy, to pass into the openings H at the back of the bridgewall, and thence upwardly, as indicated by the arrow, in which course it is brought into contact with the inflowing air from the door F. The steam-jet may or may not be employed; but I prefer to use it, as thereby a large volume of air may be admitted above the grate when introducing fresh fuel.

\Vhere the perforations H extend entirely through the bridgewall, as shown in Fig. 1, I prefer to slant them downwardly toward the rear, as I have found in my experience that much better results are thereby obtained than when they are made horizontal.

One important advantage in the novel construction of said bridge-wall is that a large volume of air is admitted below the grate and is not brought into contact with the fuel or flame until it reaches the point where itis most needed. This obviates the danger of chilling the furnace, which is likely to occur when too large a draft is admitted above the grate.

By properly adjusting the slides in the doors E and F, I am enabled to produce a perfect and complete combustion of the fuel and thus the heated gases in the combustion-chamber render the furnace wholly smokeless. may return and commingle with the fresh air Having thus described my invention, I entering from the opposite side and passing claimout through said top opening, substantially as 5 The combination, with afurnace, of a bridgeshown and described.

wall having a chamber therein extending con- T tinuously from a point at or near the bottom VILLTAM RAFFERTK' of the wall to an opening at its top, of the \Vitnesses: permanent openings H H in a plane below D. H. FLETCHER,

10 the level of the grate, whereby a portion of J. B. HALPENNY. 

